The fabrication of a semiconductor device involves a plurality of discrete and complex processes. In certain processes, it may be advantageous to heat the substrate so that the process achieves the desired result. One method of heating the substrate is through the use of light emitting diodes (LEDs). In many instances, LEDs are fabricated using gallium and nitrogen (GaN) or indium nitride and gallium nitride (InGaN). These LEDs emit light at a wavelength that is related to the bandgap energy between the p-type material and the n-type material. Thus, for LEDs fabricated using GaN and InGaN, the wavelengths tend to be about 450-500 nm.
Advancements in this technology, including discoveries in the appropriate doping of indium in the gallium nitride led to the development of high brightness blue LEDs. These high brightness blue LEDs have found application in a wide range of industries, including automotive headlights and household light bulbs.
Advantageously, the wavelengths emitted by blue LEDs are also readily absorbed by silicon. In fact, the absorption coefficient of silicon decreases with increasing wavelength. Thus, arrays of blue LEDs have been used to preheat silicon substrates prior to processing the silicon substrate.
However, some substrate used for fabricating semiconductors are not made of silicon. These other semiconductor substrates may not readily absorb blue light in the same efficient manner done by silicon. Therefore, it would be beneficial if there were a heating system that is tailored with the substrate being processed. More particularly, it would be advantageous if there were a system for more efficiently heating silicon carbide substrates and other non-silicon substrates.